Farmers strive constantly to increase their yields and the quality of their crops, and at the same time reduce their unit cost of production. They take advantage of the latest technology available to them, such as, new varieties, new production methods, agricultural chemicals, new farm machinery, etc. They recognize the importance of the need for adequate plant nutrition, which not only includes the macronutrients, nitrogen, phosphorus and potassium, but also micronutrients.
While the term "micronutrients" is generally considered to refer to such elements or metals as boron copper, iron, manganese, molybdenum and zinc, it covers in the context of this invention particularly the metals copper, iron, manganese and zinc, that is, those micronutrient elements which when added to the soil in inorganic form tend to react with other soil components and form insoluble compounds which makes them unavailable to the growing crops; or they react with the macronutrient fertilizers, especially with phosphate-based fertilizers, to form complexes or compounds which subsequently makes them likewise unavailable to crops.
Surveys over the last decade have reported deficiencies of micronutrients in many states on one or more crops. For example, deficiencies have been observed in at least 14 states for copper, 43 for zinc, 25 for iron, and 30 for manganese. Actually, micronutrient deficiencies may exist in many other states on various crops. One can, therefore, expect that micronutrient problems will increase with continued cropping and the problems will become more acute as crop yields per acre increase.
Micronutrient elements are now being used as a tool in maintaining the productivity of our agricultural soils and in increasing the yield and quality of crops grown on them. In many cases micronutrients are not only being used to correct known deficiencies but they are also being used in programs for the maintenance of soil fertility.
Micronutrients can be applied alone as a direct soil application, as a foliar spray, or in combination with macronutrient fertilizers. It is generally accepted that it is important to prevent or correct as early as possible micronutrient shortages in crops in order to assure top yields and quality. Therefore, where previous history indicates a tendency towards a particular deficiency, correction or prevention is best accomplished through a combined application of micronutrients and macronutrients. There are obvious agronomic and economic benefits to the combined application.